If the client has multiple locations, then you may want to put the addresses in a different table, so you can use a drop down to select the address you want in lineitems.
When you create the invoice, the clients name/address should be a text field with a lookup or an auto enter calculation. Phil answers this in detail here:
Second part. Maybe you need a Location Table to track the artwork's current location, with a Transit Table as a portal, to track art movements.
Thanks. Why do I the client name twice and the address twice, but only one ID which in this case is 225?
Any reason I get repeating information?